1,098 research outputs found
Geo-environmental mapping using physiographic analysis: constraints on the evaluation of land instability and groundwater pollution hazards in the Metropolitan District of Campinas, Brazil
Geo-environmental terrain assessments and territorial zoning are useful tools for the formulation and implementation of environmental management instruments (including policy-making, planning, and enforcement of statutory regulations). They usually involve a set of procedures and techniques for delimitation, characterisation and classification of terrain units. However, terrain assessments and zoning exercises are often costly and time-consuming, particularly when encompassing large areas, which in many cases prevent local agencies in developing countries from properly benefiting from such assessments. In the present paper, a low-cost technique based on the analysis of texture of satellite imagery was used for delimitation of terrain units. The delimited units were further analysed in two test areas situated in Southeast Brazil to provide estimates of land instability and the vulnerability of groundwater to pollution hazards. The implementation incorporated procedures for inferring the influences and potential implications of tectonic fractures and other discontinuities on ground behaviour and local groundwater flow. Terrain attributes such as degree of fracturing, bedrock lithology and weathered materials were explored as indicators of ground properties. The paper also discusses constraints on- and limitations of- the approaches taken
Operative technique in robotic pancreaticoduodenectomy (RPD) at University of Illinois at Chicago (IC): U17 steps standardized technique
Background: Minimally invasive pancreaticoduodenectomy (MIPD) was introduced in the attempt to improve the outcomes of the open approach. Laparoscopic pancreaticoduodenectomy (LPD) was first reported by Gagner and Pomp (Surg Endosc 8:408–410, 1994). Unfortunately, due to its complexity and technical demand, LPD never reached widespread popularity. Since it was first performed by P. C. Giulianotti in 2001, Robotic PD (RPD) has been gaining ground among surgeons. MIPD is included as a surgical option in the latest NCCN Guidelines. However, lack of surgical standardization, however, has limited the reproducibility of MIPD and made the acquisition of the technique by other surgeons difficult. We provide an accurate description of our standardized step-by-step RDP technique. Methods: We took advantage of our 15-year long experience and > 150 cases performed to provide a step-by-step guidance of our RPD standardized technique. The description includes practical “tips and tricks” to facilitate the learning curve and assist with the teaching/evaluation process. Results: 17 surgical steps were identified as key components of the RPD procedure. The steps reflect the subdivision of the RPD into several parts which help to understand a strategy that takes into accounts specific anatomical landmarks and the demands of the robotic platform. Conclusions: Standardization is a key element of the learning curve of RPD. It can potentially provide consistent, reproducible results that can be more easily evaluated. Despite promising results, full acceptance of RPD as the ‘gold standard’ is still work in progress. Randomized-controlled trials with the application of a standardized technique are necessary to better define the role of RP
Educational step-by-step surgical video about operative technique in robotic pancreaticoduodenectomy (RPD) at University of Illinois at Chicago (UIC): 17 steps standardized technique-Lessons learned since the first worldwide RPD performed in the year 2001
Background: RPD (Robotic pancreatoduodenectomy) was first performed by P. C. Giulianotti in 2001 (Arch Surg 138(7):777-784, 2003). Since then, the complexity and lack of technique standardization has slowed down its widespread utilization. RPD has been increasingly adopted worldwide and in few centres is the preferred apporached approach by certain surgeons. Some large retrospective series are available and data seem to indicate that RPD is safe/feasible, and a valid alternative to the classic open Whipple. Our group has recently described a standardized 17 steps approach to RPD (Giulianotti et al. Surg Endosc 32(10): 4329-4336, 2018). Herin, we present an educational step-by-step surgical video with short technical/operative description to visually exemplify the RPD 17 steps technique.
Methods: The current project has been approved by our local Institutional Review Board (IRB). We edited a step-by-step video guidance of our RPD standardized technique. The data/video images were collected from a retrospective analysis of a prospectively collected database (IRB approved). The narration and the images describe hands-on operative "tips and tricks" to facilitate the learning/teaching/evaluation process.
Results: Each of the 17 surgical steps is visually represented and explained to help the in-depth understanding of the relevant surgical anatomy and the specific operative technique.
Conclusions: Educational videos descriptions like the one herein presented are a valid learning/teaching tool to implement standardized surgical approaches. Standardization is a crucial component of the learning curve. This approach can create more objective and reproducible data which might be more reliably assessed/compared across institutions and by different surgeons. Promising results are arising from several centers about RPD. However, RPD as gold standard-approach is still a matter of debate. Randomized-controlled studies (RCT) are required to better validate the precise role of RPD
The second step in the construction of a stigma scale of scale
Rationale: The issue of stigmatization is one of the most common psychosocial problems faced by people with epilepsy. Purpose: A second step towards the development of a scale to measure epilepsy stigma. Method: We applied a closed questionnaire to 12 patients and 32 relatives from the Epilepsy Outpatient Clinic at the University Hospital of Campinas. Results: The results are grouped in three main domains: medical, social and personal areas. Medical: the subjects did not know exactly what epilepsy is or how it is caused; nonetheless they know how to treat it. Social: the most important areas that people with epilepsy are discriminated are at work and social relationships. Patients also complained about their lack of freedom and limits on recreation activities. Personal Area: subjects apparently have the same feelings and thoughts about epilepsy and seizures. Conclusion: This study analyzed the most common aspects presented in the questionnaire to assess epilepsy stigma for the Brazilian culture which are the base to the elaboration of a stigma scale of epilepsy.632B39539
Critical change in the Fermi surface of iron arsenic superconductors at the onset of superconductivity
The phase diagram of a correlated material is the result of a complex
interplay between several degrees of freedom, providing a map of the material's
behavior. One can understand (and ultimately control) the material's ground
state by associating features and regions of the phase diagram, with specific
physical events or underlying quantum mechanical properties. The phase diagram
of the newly discovered iron arsenic high temperature superconductors is
particularly rich and interesting. In the AE(Fe1-xTx)2As2 class (AE being Ca,
Sr, Ba, T being transition metals), the simultaneous structural/magnetic phase
transition that occurs at elevated temperature in the undoped material, splits
and is suppressed by carrier doping, the suppression being complete around
optimal doping. A dome of superconductivity exists with apparent equal ease in
the orthorhombic / antiferromagnetic (AFM) state as well as in the tetragonal
state with no long range magnetic order. The question then is what determines
the critical doping at which superconductivity emerges, if the AFM order is
fully suppressed only at higher doping values. Here we report evidence from
angle resolved photoemission spectroscopy (ARPES) that critical changes in the
Fermi surface (FS) occur at the doping level that marks the onset of
superconductivity. The presence of the AFM order leads to a reconstruction of
the electronic structure, most significantly the appearance of the small hole
pockets at the Fermi level. These hole pockets vanish, i. e. undergo a Lifshitz
transition, at the onset of superconductivity. Superconductivity and magnetism
are competing states in the iron arsenic superconductors. In the presence of
the hole pockets superconductivity is fully suppressed, while in their absence
the two states can coexist.Comment: Updated version accepted in Nature Physic
Association between regular participation in sports and leisure time behaviors in Brazilian adolescents: A cross-sectional study
<p>Abstract</p> <p>Background</p> <p>The belief that adolescents engaged in sports increase their overall physical activity level while simultaneously decreasing physical inactivity has been the foundation of many intervention programs in developing countries. The aim of this study was to analyze the association between regular participation in sports and both active behaviors and TV viewing during leisure time.</p> <p>Methods</p> <p>A total of 1752 Brazilian adolescents (812 = male and 940 = female) participated in this study. Regular participation in sports, as well as active behaviors (exemplified by walking or cycling) and TV viewing during leisure time were assessed by means of a questionnaire. The chi-square test analyzed the association between sports practice and leisure time behaviors, and the Poisson regression with robust variance indicated the magnitude of these associations.</p> <p>Results</p> <p>The prevalence of regular participation in sports was 14.8% (95% confidence interval 13.2% to 16.5%). After adjustment for all confounders, participation in sports was associated with, at the highest frequency, cycling (PR = 2.55 [1.80–3.60]) and walking (PR = 2.69 [1.98–3.64]) during leisure time. However, there was not an association between the participation in sports and frequency of TV viewing (PR = 1.28 [0.81–2.02]).</p> <p>Conclusion</p> <p>This study presented data indicating that the regular participation in sports is positively associated with a higher frequency of physically active behaviors during leisure time. However, the results did not support the hypothesis that the engagement in sports necessarily decreases leisure time spent in TV viewing.</p
A mechanism for the inhibition of DNA-PK-mediated DNA sensing by a virus
The innate immune system is critical in the response to infection by pathogens and it is activated by pattern recognition receptors (PRRs) binding to pathogen associated molecular patterns (PAMPs). During viral infection, the direct recognition of the viral nucleic acids, such as the genomes of DNA viruses, is very important for activation of innate immunity. Recently, DNA-dependent protein kinase (DNA-PK), a heterotrimeric complex consisting of the Ku70/Ku80 heterodimer and the catalytic subunit DNA-PKcs was identified as a cytoplasmic PRR for DNA that is important for the innate immune response to intracellular DNA and DNA virus infection. Here we show that vaccinia virus (VACV) has evolved to inhibit this function of DNA-PK by expression of a highly conserved protein called C16, which was known to contribute to virulence but by an unknown mechanism. Data presented show that C16 binds directly to the Ku heterodimer and thereby inhibits the innate immune response to DNA in fibroblasts, characterised by the decreased production of cytokines and chemokines. Mechanistically, C16 acts by blocking DNA-PK binding to DNA, which correlates with reduced DNA-PK-dependent DNA sensing. The C-terminal region of C16 is sufficient for binding Ku and this activity is conserved in the variola virus (VARV) orthologue of C16. In contrast, deletion of 5 amino acids in this domain is enough to knockout this function from the attenuated vaccine strain modified vaccinia virus Ankara (MVA). In vivo a VACV mutant lacking C16 induced higher levels of cytokines and chemokines early after infection compared to control viruses, confirming the role of this virulence factor in attenuating the innate immune response. Overall this study describes the inhibition of DNA-PK-dependent DNA sensing by a poxvirus protein, adding to the evidence that DNA-PK is a critical component of innate immunity to DNA viruses
Tissue plasminogen activator-treated patients with acute ischemic stroke in the pioneer public service of Rio de Janeiro: a comparative profile with the NINDS study
Vibrational analysis of d-PCL(530)/siloxane based hybrids doped with two lithium salts
Published online: 22 May 2013The present study has been focused on environmentally friendly sol-gel derived electrolytes based on a di-urethane cross-linked d-PCL(530)/siloxane network (where d represents di, PCL identifies the poly(ε–caprolactone) biopolymer and 530 is the average molecular weight in g.mol-1) doped with a wide range of concentration of lithium perchlorate (LiClO4) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Fourier Transform Infrared and Raman (FT-IR and FT-Raman, respectively) spectroscopies have been applied to evaluate the extent of ionic association. Characteristic bands of the PCL(530) segments, of the urethane cross-links and of the anions have been examined to gain insight into the cation/biopolymer, cation/anion and cation/cross-link interactions. In both electrolyte systems “free” ions and contact ions have been identified. The addition of salt modifies the hydrogen-bonded array of the host matrix, causing the destruction/formation of the urethane/urethane aggregates.Fundação para a Ciência e a Tecnologia (FCT
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